Implement the FDR forwarder proxy service used during restore of recent iOS versions.

9 files changed, 1179 insertions, 2 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index d823c2c..f169708 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -21,7 +21,7 @@ AM_LDADD = $(AC_LDADD)
 
 bin_PROGRAMS = idevicerestore
 
-idevicerestore_SOURCES = idevicerestore.c common.c tss.c fls.c mbn.c img3.c img4.c ipsw.c normal.c dfu.c recovery.c restore.c asr.c limera1n.c download.c locking.c
+idevicerestore_SOURCES = idevicerestore.c common.c tss.c fls.c mbn.c img3.c img4.c ipsw.c normal.c dfu.c recovery.c restore.c asr.c fdr.c limera1n.c download.c locking.c socket.c thread.c
 idevicerestore_CFLAGS = $(AM_CFLAGS)
 idevicerestore_LDFLAGS = $(AM_LDFLAGS)
 idevicerestore_LDADD = $(AM_LDADD)
diff --git a/src/fdr.c b/src/fdr.c
new file mode 100644
index 0000000..8d5c9c5
--- /dev/null
+++ b/src/fdr.c
@@ -0,0 +1,491 @@
+/*
+ * fdr.c
+ * Connection proxy service used by FDR
+ *
+ * Copyright (c) 2014 BALATON Zoltan. All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <libimobiledevice/libimobiledevice.h>
+
+#include "socket.h" /* from libimobiledevice/common */
+#include "common.h"
+#include "idevicerestore.h"
+#include "fdr.h"
+
+#define CTRL_PROTO_VERSION 2
+#define CTRL_PORT 0x43a /*14852*/
+#define CTRLCMD  "BeginCtrl"
+#define HELLOCMD "HelloConn"
+
+#define FDR_SYNC_MSG  0x1
+#define FDR_PROXY_MSG 0x105
+#define FDR_PLIST_MSG 0xbbaa
+
+static uint64_t conn_port;
+static int serial;
+
+static int fdr_receive_plist(fdr_client_t fdr, plist_t* data);
+static int fdr_send_plist(fdr_client_t fdr, plist_t data);
+static int fdr_ctrl_handshake(fdr_client_t fdr);
+static int fdr_sync_handshake(fdr_client_t fdr);
+static int fdr_handle_sync_cmd(fdr_client_t fdr);
+static int fdr_handle_plist_cmd(fdr_client_t fdr);
+static int fdr_handle_proxy_cmd(fdr_client_t fdr);
+
+int fdr_connect(idevice_t device, fdr_type_t type, fdr_client_t* fdr)
+{
+	int res = -1, i = 0;
+	int attempts = 10;
+	idevice_connection_t connection = NULL;
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	uint16_t port = (type == FDR_CONN ? conn_port : CTRL_PORT);
+
+	*fdr = NULL;
+
+	debug("Connecting to FDR client at port %u\n", port);
+
+	for (i = 1; i <= attempts; i++) {
+		device_error = idevice_connect(device, port, &connection);
+		if (device_error == IDEVICE_E_SUCCESS) {
+			break;
+		}
+
+		if (i >= attempts) {
+			error("ERROR: Unable to connect to FDR client (%d)\n", device_error);
+			return -1;
+		}
+
+		sleep(2);
+		debug("Retrying connection...\n");
+	}
+
+	fdr_client_t fdr_loc = calloc(1, sizeof(struct fdr_client));
+	if (!fdr_loc) {
+		error("ERROR: Unable to allocate memory\n");
+		return -1;
+	}
+	fdr_loc->connection = connection;
+	fdr_loc->device = device;
+	fdr_loc->type = type;
+
+	/* Do handshake */
+	if (type == FDR_CTRL)
+		res = fdr_ctrl_handshake(fdr_loc);
+	else if (type == FDR_CONN)
+		res = fdr_sync_handshake(fdr_loc);
+
+	if (res) {
+		fdr_free(fdr_loc);
+		return -1;
+	}
+
+	*fdr = fdr_loc;
+
+	return 0;
+}
+
+void fdr_free(fdr_client_t fdr)
+{
+	if (!fdr)
+		return;
+
+	if (fdr->connection) {
+		idevice_disconnect(fdr->connection);
+		fdr->connection = NULL;
+	}
+	free(fdr);
+	fdr = NULL;
+}
+
+int fdr_poll_and_handle_message(fdr_client_t fdr)
+{
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	uint32_t bytes = 0;
+	uint16_t cmd;
+
+	if (!fdr) {
+		error("ERROR: Invalid FDR client\n");
+		return -1;
+	}
+
+	device_error = idevice_connection_receive_timeout(fdr->connection, (char *)&cmd, sizeof(cmd), &bytes, 20000);
+	if (device_error != IDEVICE_E_SUCCESS) {
+		error("ERROR: Unable to receive message from FDR %p (%d). %u/%d bytes\n",
+		      fdr, device_error, bytes, sizeof(cmd));
+		return -1;
+	} else if (bytes != sizeof(cmd)) {
+		debug("FDR %p timeout waiting for command\n", fdr);
+		return 0;
+	}
+
+	if (cmd == FDR_SYNC_MSG) {
+		debug("FDR %p got sync message\n", fdr);
+		return fdr_handle_sync_cmd(fdr);
+	}
+
+	if (cmd == FDR_PROXY_MSG) {
+		debug("FDR %p got proxy message\n", fdr);
+		return fdr_handle_proxy_cmd(fdr);
+	}
+
+	if (cmd == FDR_PLIST_MSG) {
+		debug("FDR %p got plist message\n", fdr);
+		return fdr_handle_plist_cmd(fdr);
+	}
+
+	error("WARNING: FDR %p received unknown packet %#x of size %u\n", fdr, cmd, bytes);
+	return 0;
+}
+
+void *fdr_listener_thread(void *cdata)
+{
+	fdr_client_t fdr = cdata;
+	int res;
+
+	while (1) {
+		debug("FDR %p waiting for message...\n", fdr);
+		res = fdr_poll_and_handle_message(fdr);
+		if (fdr->type == FDR_CTRL && res >= 0)
+			continue; // main thread should always retry
+		if (res != 0)
+			break;
+	}
+	debug("FDR %p terminating...\n", fdr);
+	fdr_free(fdr);
+	return (void *)res;
+}
+
+static int fdr_receive_plist(fdr_client_t fdr, plist_t* data)
+{
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	uint32_t len, bytes = 0;
+	char* buf = NULL;
+
+	device_error = idevice_connection_receive(fdr->connection, (char*)&len, sizeof(len), &bytes);
+	if (device_error != IDEVICE_E_SUCCESS) {
+		error("ERROR: Unable to receive packet length from FDR (%d)\n", device_error);
+		return -1;
+	}
+
+	buf = calloc(1, len);
+	if (!buf) {
+		error("ERROR: Unable to allocate memory for FDR receive buffer\n");
+		return -1;
+	}
+
+	device_error = idevice_connection_receive(fdr->connection, buf, len, &bytes);
+	if (device_error != IDEVICE_E_SUCCESS) {
+		error("ERROR: Unable to receive data from FDR\n");
+		free(buf);
+		return -1;
+	}
+	plist_from_bin(buf, bytes, data);
+	free(buf);
+
+	debug("FDR Received %d bytes\n", bytes);
+
+	return 0;
+}
+
+static int fdr_send_plist(fdr_client_t fdr, plist_t data)
+{
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	char *buf = NULL;
+	uint32_t len = 0, bytes = 0;
+
+	if (!data)
+		return -1;
+
+	plist_to_bin(data, &buf, &len);
+	if (!buf)
+		return -1;
+
+	debug("FDR sending %d bytes:\n", len);
+	if (idevicerestore_debug)
+		debug_plist(data);
+	device_error = idevice_connection_send(fdr->connection, (char *)&len, sizeof(len), &bytes);
+	if (device_error != IDEVICE_E_SUCCESS || bytes != sizeof(len)) {
+		error("ERROR: FDR unable to send data length. (%d) Sent %u of %u bytes.\n", 
+		      device_error, bytes, sizeof(len));
+		free(buf);
+		return -1;
+	}
+	device_error = idevice_connection_send(fdr->connection, buf, len, &bytes);
+	free(buf);
+	if (device_error != IDEVICE_E_SUCCESS || bytes != len) {
+		error("ERROR: FDR unable to send data (%d). Sent %u of %u bytes.\n",
+		      device_error, bytes, len);
+		return -1;
+	}
+
+	debug("FDR Sent %d bytes\n", bytes);
+	return 0;
+}
+
+static int fdr_ctrl_handshake(fdr_client_t fdr)
+{
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	uint32_t bytes = 0, len = sizeof(CTRLCMD);
+	plist_t dict, node;
+	int res;
+
+	debug("About to do ctrl handshake\n");
+
+	device_error = idevice_connection_send(fdr->connection, CTRLCMD, len, &bytes);
+	if (device_error != IDEVICE_E_SUCCESS || bytes != len) {
+		error("ERROR: FDR unable to send BeginCtrl. Sent %u of %u bytes.\n", bytes, len);
+		return -1;
+	}
+
+	dict = plist_new_dict();
+	plist_dict_set_item(dict, "Command", plist_new_string(CTRLCMD));
+	plist_dict_set_item(dict, "CtrlProtoVersion", plist_new_uint(CTRL_PROTO_VERSION));
+	res = fdr_send_plist(fdr, dict);
+	plist_free(dict);
+	if (res) {
+		error("ERROR: FDR could not send Begin command.\n");
+		return -1;
+	}
+
+	if (fdr_receive_plist(fdr, &dict)) {
+		error("ERROR: FDR did not get Begin command reply.\n");
+		return -1;
+	}
+	if (idevicerestore_debug)
+		debug_plist(dict);
+	node = plist_dict_get_item(dict, "ConnPort");
+	if (node && plist_get_node_type(node) == PLIST_UINT)
+		plist_get_uint_val(node, &conn_port);
+	else {
+		error("ERROR: Could not get FDR ConnPort value\n");
+		return -1;
+	}
+
+	plist_free(dict);
+
+	debug("Ctrl handshake done (ConnPort = %u)\n", conn_port);
+
+	return 0;
+}
+
+static int fdr_sync_handshake(fdr_client_t fdr)
+{
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	uint32_t bytes = 0, len = sizeof(HELLOCMD);
+	plist_t reply;
+
+	device_error = idevice_connection_send(fdr->connection, HELLOCMD, len, &bytes);
+	if (device_error != IDEVICE_E_SUCCESS || bytes != len) {
+		error("ERROR: FDR unable to send Hello. Sent %u of %u bytes.\n", bytes, len);
+		return -1;
+	}
+	if (fdr_receive_plist(fdr, &reply)) {
+		error("ERROR: FDR did not get Hello reply.\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int fdr_handle_sync_cmd(fdr_client_t fdr_ctrl)
+{
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	fdr_client_t fdr;
+	thread_t fdr_thread = 0;
+	int res = 0;
+	uint32_t bytes = 0;
+	char buf[4096];
+
+	device_error = idevice_connection_receive(fdr_ctrl->connection, buf, sizeof(buf), &bytes);
+	if (device_error != IDEVICE_E_SUCCESS || bytes != 2) {
+		error("ERROR: Unexpected data from FDR\n");
+		return -1;
+	}
+	/* Open a new connection and wait for messages on it */
+	if (fdr_connect(fdr_ctrl->device, FDR_CONN, &fdr)) {
+		error("ERROR: Failed to connect to FDR port\n");
+		return -1;
+	}
+	debug("FDR connected in reply to sync message, starting command thread\n");
+	res = thread_create(&fdr_thread, fdr_listener_thread, fdr);
+	if(res) {
+		error("ERROR: Failed to start FDR command thread\n");
+		fdr_free(fdr);
+	}
+	return res;
+}
+
+static int fdr_handle_plist_cmd(fdr_client_t fdr)
+{
+	int res = 0;
+	plist_t dict;
+
+	if (fdr_receive_plist(fdr, &dict)) {
+		error("ERROR: FDR %p could not receive plist command.\n", fdr);
+		return -1;
+	}
+	plist_t node = plist_dict_get_item(dict, "Command");
+	if (!node || (plist_get_node_type(node) != PLIST_STRING)) {
+		error("ERROR: FDR %p Could not find Command in plist command\n", fdr);
+		plist_free(dict);
+		return -1;
+	}
+	char *command = NULL;
+	plist_get_string_val(node, &command);
+	plist_free(dict);
+
+	if (!command) {
+		info("FDR %p received empty plist command\n", fdr);
+		return -1;
+	}
+
+	if (!strcmp(command, "Ping")) {
+		dict = plist_new_dict();
+		plist_dict_set_item(dict, "Pong", plist_new_bool(1));
+		res = fdr_send_plist(fdr, dict);
+		plist_free(dict);
+		if (res) {
+			error("ERROR: FDR %p could not send Ping command reply.\n", fdr);
+			free(command);
+			return -1;
+		}
+	} else {
+ 		error("WARNING: FDR %p received unknown plist command: %s\n", fdr, command);
+		free(command);
+		return -1;
+	}
+
+	free(command);
+	return 1; /* should terminate thread */
+}
+
+static int fdr_handle_proxy_cmd(fdr_client_t fdr)
+{
+	idevice_error_t device_error = IDEVICE_E_SUCCESS;
+	char buf[16*1024];
+	uint32_t sent = 0, bytes = 0;
+	char *host = NULL;
+	uint16_t port = 0;
+
+	device_error = idevice_connection_receive(fdr->connection, buf, sizeof(buf), &bytes);
+	if (device_error != IDEVICE_E_SUCCESS) {
+		error("ERROR: FDR %p failed to read data for proxy command\n", fdr);
+		return -1;
+	}
+	debug("Got proxy command with %u bytes\n", bytes);
+
+	/* Just return success here unconditionally because we don't know
+	 * anything else and we will eventually abort on failure anyway */
+	uint16_t ack = 5;
+	device_error = idevice_connection_send(fdr->connection, (char *)&ack, sizeof(ack), &sent);
+	if (device_error != IDEVICE_E_SUCCESS || sent != sizeof(ack)) {
+		error("ERROR: FDR %p unable to send ack. Sent %u of %u bytes.\n",
+		      fdr, sent, sizeof(ack));
+		return -1;
+	}
+
+	if (bytes < 3) {
+		debug("FDR %p proxy command data too short, retrying\n", fdr);
+		return fdr_poll_and_handle_message(fdr);
+	}
+
+	/* ack command data too */
+	device_error = idevice_connection_send(fdr->connection, buf, bytes, &sent);
+	if (device_error != IDEVICE_E_SUCCESS || sent != bytes) {
+		error("ERROR: FDR %p unable to send data. Sent %u of %u bytes.\n",
+		      fdr, sent, bytes);
+		return -1;
+	}
+
+	/* Now try to handle actual messages */
+	/* Connect: 0 3 hostlen <host> <port> */
+	if (buf[0] == 0 && buf[1] == 3) {
+		uint16_t *p = (uint16_t *)&buf[bytes - 2];
+		port = be16toh(*p);
+		buf[bytes - 2] = '\0';
+		host = strdup(&buf[3]);
+		debug("FDR %p Proxy connect request to %s:%u\n", fdr, host, port);
+	}
+
+	if (!host || !buf[2]) /* missing or zero length host name */
+		return 0;
+
+	/* else wait for messages and forward them */
+	int sockfd = socket_connect(host, port);
+	free(host);
+	if (sockfd < 0) {
+		error("ERROR: Failed to connect socket: %s\n", strerror(errno));
+		return -1;
+	}
+
+	int res = 0, bytes_ret;
+	while (1) {
+		bytes = 0;
+		device_error = idevice_connection_receive_timeout(fdr->connection, buf, sizeof(buf), &bytes, 100);
+		if (device_error != IDEVICE_E_SUCCESS) {
+			error("ERROR: FDR %p Unable to receive proxy payload (%d)\n", fdr, device_error);
+			res = -1;
+			break;
+		} else if (!bytes) {
+			//debug("WARNING: Timeout waiting for proxy payload. %p\n", fdr);
+		}
+		if (bytes) {
+			debug("FDR %p got payload of %u bytes, now try to proxy it\n", fdr, bytes);
+			debug("Sending %u bytes of data\n", bytes);
+			sent = socket_send(sockfd, buf, bytes);
+			if (sent != bytes) {
+				error("ERROR: Sending proxy payload failed: %s\n", strerror(errno));
+				socket_close(sockfd);
+				res = -1;
+				break;
+			}
+		}
+		bytes_ret = socket_receive_timeout(sockfd, buf, sizeof(buf), 0, 100);
+		if (bytes_ret < 0) {
+			if (errno)
+				error("ERROR: FDR %p receiving proxy payload failed: %s\n",
+				      fdr, strerror(errno));
+			else
+				res = 1; /* close connection if no data with no error */
+			break;
+		}
+
+		bytes = bytes_ret;
+		if (bytes) {
+			debug("FDR %p Received %u bytes reply data,%s sending to device\n",
+			      fdr, bytes, (bytes ? "" : " not"));
+
+			device_error = idevice_connection_send(fdr->connection, buf, bytes, &sent);
+			if (device_error != IDEVICE_E_SUCCESS || bytes != sent) {
+				error("ERROR: FDR %p unable to send data (%d). Sent %u of %u bytes.\n",
+				      fdr, device_error, sent, bytes);
+				res = -1;
+				break;
+			}
+		} else serial++;
+	}
+	socket_close(sockfd);
+	return res;
+}
diff --git a/src/fdr.h b/src/fdr.h
new file mode 100644
index 0000000..6139240
--- /dev/null
+++ b/src/fdr.h
@@ -0,0 +1,53 @@
+/*
+ * fdr.h
+ * Functions for handling FDR connections
+ *
+ * Copyright (c) 2014 BALATON Zoltan. All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef IDEVICERESTORE_FDR_H
+#define IDEVICERESTORE_FDR_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <libimobiledevice/libimobiledevice.h>
+#include "thread.h" /* from libimobiledevice/common */
+
+typedef enum {
+	FDR_CTRL,
+	FDR_CONN
+} fdr_type_t;
+
+struct fdr_client {
+	idevice_connection_t connection;
+	idevice_t device;
+	fdr_type_t type;
+};
+typedef struct fdr_client *fdr_client_t;
+
+int fdr_connect(idevice_t device, fdr_type_t type, fdr_client_t *fdr);
+void fdr_free(fdr_client_t fdr);
+int fdr_poll_and_handle_message(fdr_client_t fdr);
+void *fdr_listener_thread(void *cdata);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/restore.c b/src/restore.c
index 3d70017..9775562 100644
--- a/src/restore.c
+++ b/src/restore.c
@@ -31,6 +31,7 @@
 
 #include "idevicerestore.h"
 #include "asr.h"
+#include "fdr.h"
 #include "fls.h"
 #include "mbn.h"
 #include "tss.h"
@@ -1663,6 +1664,7 @@ int restore_device(struct idevicerestore_client_t* client, plist_t build_identit
 	idevice_t device = NULL;
 	restored_client_t restore = NULL;
 	restored_error_t restore_error = RESTORE_E_SUCCESS;
+	thread_t fdr_thread = 0;
 
 	restore_finished = 0;
 
@@ -1743,6 +1745,25 @@ int restore_device(struct idevicerestore_client_t* client, plist_t build_identit
 		client->restore->bbtss = plist_copy(client->tss);
 	}
 
+	node = plist_access_path(build_identity, 2, "Info", "FDRSupport");
+	if (node && plist_get_node_type(node) == PLIST_BOOLEAN) {
+		uint8_t b = 0;
+		plist_get_bool_val(node, &b);
+		if (b) {
+			fdr_client_t fdr_control_channel = NULL;
+			info("FDRSupport indicated, starting FDR listener thread\n");
+			if (!fdr_connect(device, FDR_CTRL, &fdr_control_channel)) {
+				if(thread_create(&fdr_thread, fdr_listener_thread, fdr_control_channel)) {
+					error("ERROR: Failed to start FDR listener thread\n");
+					fdr_thread = 0; /* undefined after failure */
+				}
+			} else {
+				error("ERROR: Failed to start FDR Ctrl channel\n");
+				// FIXME: We might want to return failure here as it will likely fail
+			}
+		}
+	}
+
 	plist_t opts = plist_new_dict();
 	// FIXME: required?
 	//plist_dict_set_item(opts, "AuthInstallRestoreBehavior", plist_new_string("Erase"));
diff --git a/src/restore.h b/src/restore.h
index 7b3be7f..8dc9a45 100644
--- a/src/restore.h
+++ b/src/restore.h
@@ -58,7 +58,7 @@ int restore_send_kernelcache(restored_client_t restore, struct idevicerestore_cl
 int restore_device(struct idevicerestore_client_t* client, plist_t build_identity, const char* filesystem);
 int restore_open_with_timeout(struct idevicerestore_client_t* client);
 int restore_send_filesystem(struct idevicerestore_client_t* client, idevice_t device, const char* filesystem);
-
+int restore_send_fdr_trust_data(restored_client_t restore, idevice_t device);
 
 #ifdef __cplusplus
 }
diff --git a/src/socket.c b/src/socket.c
new file mode 100644
index 0000000..c35de33
--- /dev/null
+++ b/src/socket.c
@@ -0,0 +1,392 @@
+/*
+ * socket.c
+ *
+ * Copyright (c) 2012 Martin Szulecki All Rights Reserved.
+ * Copyright (c) 2012 Nikias Bassen All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#ifdef WIN32
+#include <winsock2.h>
+#include <windows.h>
+static int wsa_init = 0;
+#else
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#endif
+#include "socket.h"
+
+#define RECV_TIMEOUT 20000
+
+static int verbose = 0;
+
+void socket_set_verbose(int level)
+{
+	verbose = level;
+}
+
+#ifndef WIN32
+int socket_create_unix(const char *filename)
+{
+	struct sockaddr_un name;
+	int sock;
+	size_t size;
+
+	// remove if still present
+	unlink(filename);
+
+	/* Create the socket. */
+	sock = socket(PF_LOCAL, SOCK_STREAM, 0);
+	if (sock < 0) {
+		perror("socket");
+		return -1;
+	}
+
+	/* Bind a name to the socket. */
+	name.sun_family = AF_LOCAL;
+	strncpy(name.sun_path, filename, sizeof(name.sun_path));
+	name.sun_path[sizeof(name.sun_path) - 1] = '\0';
+
+	/* The size of the address is
+	   the offset of the start of the filename,
+	   plus its length,
+	   plus one for the terminating null byte.
+	   Alternatively you can just do:
+	   size = SUN_LEN (&name);
+	 */
+	size = (offsetof(struct sockaddr_un, sun_path)
+			+ strlen(name.sun_path) + 1);
+
+	if (bind(sock, (struct sockaddr *) &name, size) < 0) {
+		perror("bind");
+		socket_close(sock);
+		return -1;
+	}
+
+	if (listen(sock, 10) < 0) {
+		perror("listen");
+		socket_close(sock);
+		return -1;
+	}
+
+	return sock;
+}
+
+int socket_connect_unix(const char *filename)
+{
+	struct sockaddr_un name;
+	int sfd = -1;
+	size_t size;
+	struct stat fst;
+
+	// check if socket file exists...
+	if (stat(filename, &fst) != 0) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: stat '%s': %s\n", __func__, filename,
+					strerror(errno));
+		return -1;
+	}
+	// ... and if it is a unix domain socket
+	if (!S_ISSOCK(fst.st_mode)) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: File '%s' is not a socket!\n", __func__,
+					filename);
+		return -1;
+	}
+	// make a new socket
+	if ((sfd = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: socket: %s\n", __func__, strerror(errno));
+		return -1;
+	}
+	// and connect to 'filename'
+	name.sun_family = AF_LOCAL;
+	strncpy(name.sun_path, filename, sizeof(name.sun_path));
+	name.sun_path[sizeof(name.sun_path) - 1] = 0;
+
+	size = (offsetof(struct sockaddr_un, sun_path)
+			+ strlen(name.sun_path) + 1);
+
+	if (connect(sfd, (struct sockaddr *) &name, size) < 0) {
+		socket_close(sfd);
+		if (verbose >= 2)
+			fprintf(stderr, "%s: connect: %s\n", __func__,
+					strerror(errno));
+		return -1;
+	}
+
+	return sfd;
+}
+#endif
+
+int socket_create(uint16_t port)
+{
+	int sfd = -1;
+	int yes = 1;
+#ifdef WIN32
+	WSADATA wsa_data;
+	if (!wsa_init) {
+		if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
+			fprintf(stderr, "WSAStartup failed!\n");
+			ExitProcess(-1);
+		}
+		wsa_init = 1;
+	}
+#endif
+	struct sockaddr_in saddr;
+
+	if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
+		perror("socket()");
+		return -1;
+	}
+
+	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	memset((void *) &saddr, 0, sizeof(saddr));
+	saddr.sin_family = AF_INET;
+	saddr.sin_addr.s_addr = htonl(INADDR_ANY);
+	saddr.sin_port = htons(port);
+
+	if (0 > bind(sfd, (struct sockaddr *) &saddr, sizeof(saddr))) {
+		perror("bind()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	if (listen(sfd, 1) == -1) {
+		perror("listen()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	return sfd;
+}
+
+int socket_connect(const char *addr, uint16_t port)
+{
+	int sfd = -1;
+	int yes = 1;
+	struct hostent *hp;
+	struct sockaddr_in saddr;
+#ifdef WIN32
+	WSADATA wsa_data;
+	if (!wsa_init) {
+		if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
+			fprintf(stderr, "WSAStartup failed!\n");
+			ExitProcess(-1);
+		}
+		wsa_init = 1;
+	}
+#endif
+
+	if (!addr) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if ((hp = gethostbyname(addr)) == NULL) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: unknown host '%s'\n", __func__, addr);
+		return -1;
+	}
+
+	if (!hp->h_addr) {
+		if (verbose >= 2)
+			fprintf(stderr, "%s: gethostbyname returned NULL address!\n",
+					__func__);
+		return -1;
+	}
+
+	if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
+		perror("socket()");
+		return -1;
+	}
+
+	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(int)) == -1) {
+		perror("setsockopt()");
+		socket_close(sfd);
+		return -1;
+	}
+
+	memset((void *) &saddr, 0, sizeof(saddr));
+	saddr.sin_family = AF_INET;
+	saddr.sin_addr.s_addr = *(uint32_t *) hp->h_addr;
+	saddr.sin_port = htons(port);
+
+	if (connect(sfd, (struct sockaddr *) &saddr, sizeof(saddr)) < 0) {
+		perror("connect");
+		socket_close(sfd);
+		return -2;
+	}
+
+	return sfd;
+}
+
+int socket_check_fd(int fd, fd_mode fdm, unsigned int timeout)
+{
+	fd_set fds;
+	int sret;
+	int eagain;
+	struct timeval to;
+	struct timeval *pto;
+
+	if (fd <= 0) {
+		if (verbose >= 2)
+			fprintf(stderr, "ERROR: invalid fd in check_fd %d\n", fd);
+		return -1;
+	}
+
+	FD_ZERO(&fds);
+	FD_SET(fd, &fds);
+
+	if (timeout > 0) {
+		to.tv_sec = (time_t) (timeout / 1000);
+		to.tv_usec = (time_t) ((timeout - (to.tv_sec * 1000)) * 1000);
+		pto = &to;
+	} else {
+		pto = NULL;
+	}
+
+	sret = -1;
+
+	do {
+		eagain = 0;
+		switch (fdm) {
+		case FDM_READ:
+			sret = select(fd + 1, &fds, NULL, NULL, pto);
+			break;
+		case FDM_WRITE:
+			sret = select(fd + 1, NULL, &fds, NULL, pto);
+			break;
+		case FDM_EXCEPT:
+			sret = select(fd + 1, NULL, NULL, &fds, pto);
+			break;
+		default:
+			return -1;
+		}
+
+		if (sret < 0) {
+			switch (errno) {
+			case EINTR:
+				// interrupt signal in select
+				if (verbose >= 2)
+					fprintf(stderr, "%s: EINTR\n", __func__);
+				eagain = 1;
+				break;
+			case EAGAIN:
+				if (verbose >= 2)
+					fprintf(stderr, "%s: EAGAIN\n", __func__);
+				break;
+			default:
+				if (verbose >= 2)
+					fprintf(stderr, "%s: select failed: %s\n", __func__,
+							strerror(errno));
+				return -1;
+			}
+		}
+	} while (eagain);
+
+	return sret;
+}
+
+int socket_accept(int fd, uint16_t port)
+{
+#ifdef WIN32
+	int addr_len;
+#else
+	socklen_t addr_len;
+#endif
+	int result;
+	struct sockaddr_in addr;
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	addr.sin_port = htons(port);
+
+	addr_len = sizeof(addr);
+	result = accept(fd, (struct sockaddr*)&addr, &addr_len);
+
+	return result;
+}
+
+int socket_shutdown(int fd, int how)
+{
+	return shutdown(fd, how);
+}
+
+int socket_close(int fd) {
+#ifdef WIN32
+	return closesocket(fd);
+#else
+	return close(fd);
+#endif
+}
+
+int socket_receive(int fd, void *data, size_t length)
+{
+	return socket_receive_timeout(fd, data, length, 0, RECV_TIMEOUT);
+}
+
+int socket_peek(int fd, void *data, size_t length)
+{
+	return socket_receive_timeout(fd, data, length, MSG_PEEK, RECV_TIMEOUT);
+}
+
+int socket_receive_timeout(int fd, void *data, size_t length, int flags,
+					 unsigned int timeout)
+{
+	int res;
+	int result;
+
+	// check if data is available
+	res = socket_check_fd(fd, FDM_READ, timeout);
+	if (res <= 0) {
+		return res;
+	}
+	// if we get here, there _is_ data available
+	result = recv(fd, data, length, flags);
+	if (res > 0 && result == 0) {
+		// but this is an error condition
+		if (verbose >= 3)
+			fprintf(stderr, "%s: fd=%d recv returned 0\n", __func__, fd);
+		return -EAGAIN;
+	}
+	if (result < 0) {
+		return -errno;
+	}
+	return result;
+}
+
+int socket_send(int fd, void *data, size_t length)
+{
+	return send(fd, data, length, 0);
+}
diff --git a/src/socket.h b/src/socket.h
new file mode 100644
index 0000000..c2b2599
--- /dev/null
+++ b/src/socket.h
@@ -0,0 +1,65 @@
+/*
+ * socket.h
+ *
+ * Copyright (c) 2012 Martin Szulecki All Rights Reserved.
+ * Copyright (c) 2012 Nikias Bassen All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+
+#ifndef __SOCKET_SOCKET_H
+#define __SOCKET_SOCKET_H
+
+#include <stdlib.h>
+#include <stdint.h>
+
+enum fd_mode {
+	FDM_READ,
+	FDM_WRITE,
+	FDM_EXCEPT
+};
+typedef enum fd_mode fd_mode;
+
+#ifdef WIN32
+#include <winsock2.h>
+#define SHUT_RD SD_READ
+#define SHUT_WR SD_WRITE
+#define SHUT_RDWR SD_BOTH
+#else
+#include <sys/socket.h>
+#endif
+
+#ifndef WIN32
+int socket_create_unix(const char *filename);
+int socket_connect_unix(const char *filename);
+#endif
+int socket_create(uint16_t port);
+int socket_connect(const char *addr, uint16_t port);
+int socket_check_fd(int fd, fd_mode fdm, unsigned int timeout);
+int socket_accept(int fd, uint16_t port);
+
+int socket_shutdown(int fd, int how);
+int socket_close(int fd);
+
+int socket_receive(int fd, void *data, size_t size);
+int socket_peek(int fd, void *data, size_t size);
+int socket_receive_timeout(int fd, void *data, size_t size, int flags,
+					 unsigned int timeout);
+
+int socket_send(int fd, void *data, size_t size);
+
+void socket_set_verbose(int level);
+
+#endif	/* __SOCKET_SOCKET_H */
diff --git a/src/thread.c b/src/thread.c
new file mode 100644
index 0000000..d6d6c1a
--- /dev/null
+++ b/src/thread.c
@@ -0,0 +1,99 @@
+/*
+ * thread.c
+ *
+ * Copyright (c) 2012 Martin Szulecki All Rights Reserved.
+ * Copyright (c) 2012 Nikias Bassen All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+
+#include "thread.h"
+
+int thread_create(thread_t *thread, thread_func_t thread_func, void* data)
+{
+#ifdef WIN32
+	HANDLE th = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)thread_func, data, 0, NULL);
+        if (th == NULL) {
+		return -1;
+        }
+	*thread = th;
+	return 0;
+#else
+	int res = pthread_create(thread, NULL, thread_func, data);
+	return res;
+#endif
+}
+
+void thread_join(thread_t thread)
+{
+	/* wait for thread to complete */
+#ifdef WIN32
+	WaitForSingleObject(thread, INFINITE);
+#else
+	pthread_join(thread, NULL);
+#endif
+}
+
+void mutex_init(mutex_t* mutex)
+{
+#ifdef WIN32
+	InitializeCriticalSection(mutex);
+#else
+	pthread_mutex_init(mutex, NULL);
+#endif
+}
+
+void mutex_destroy(mutex_t* mutex)
+{
+#ifdef WIN32
+	DeleteCriticalSection(mutex);
+#else
+	pthread_mutex_destroy(mutex);
+#endif
+}
+
+void mutex_lock(mutex_t* mutex)
+{
+#ifdef WIN32
+	EnterCriticalSection(mutex);
+#else
+	pthread_mutex_lock(mutex);
+#endif
+}
+
+void mutex_unlock(mutex_t* mutex)
+{
+#ifdef WIN32
+	LeaveCriticalSection(mutex);
+#else
+	pthread_mutex_unlock(mutex);
+#endif
+}
+
+void thread_once(thread_once_t *once_control, void (*init_routine)(void))
+{
+#ifdef WIN32
+	while (InterlockedExchange(&(once_control->lock), 1) != 0) {
+		Sleep(1);
+	}
+	if (!once_control->state) {
+		once_control->state = 1;
+		init_routine();
+	}
+	InterlockedExchange(&(once_control->lock), 0);
+#else
+	pthread_once(once_control, init_routine);
+#endif	
+}
diff --git a/src/thread.h b/src/thread.h
new file mode 100644
index 0000000..9b15cc4
--- /dev/null
+++ b/src/thread.h
@@ -0,0 +1,56 @@
+/*
+ * thread.h
+ *
+ * Copyright (c) 2012 Martin Szulecki All Rights Reserved.
+ * Copyright (c) 2012 Nikias Bassen All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+
+#ifndef __THREAD_H
+#define __THREAD_H
+
+#ifdef WIN32
+#include <windows.h>
+typedef HANDLE thread_t;
+typedef CRITICAL_SECTION mutex_t;
+typedef volatile struct {
+	LONG lock;
+	int state;
+} thread_once_t;
+#define THREAD_ONCE_INIT {0, 0}
+#define THREAD_ID GetCurrentThreadId()
+#else
+#include <pthread.h>
+typedef pthread_t thread_t;
+typedef pthread_mutex_t mutex_t;
+typedef pthread_once_t thread_once_t;
+#define THREAD_ONCE_INIT PTHREAD_ONCE_INIT
+#define THREAD_ID pthread_self()
+#endif
+
+typedef void* (*thread_func_t)(void* data);
+
+int thread_create(thread_t* thread, thread_func_t thread_func, void* data);
+void thread_join(thread_t thread);
+
+void mutex_init(mutex_t* mutex);
+void mutex_destroy(mutex_t* mutex);
+void mutex_lock(mutex_t* mutex);
+void mutex_unlock(mutex_t* mutex);
+
+void thread_once(thread_once_t *once_control, void (*init_routine)(void));
+
+#endif